Manik engineers manufactures type snrva non return check valves for use in liquid, suction and hot gas lines in refrigeration and air conditioning plant with ammonia. This non-return check valves are also useful in refrigerating systems with fluorinated refrigerants. When the snrva is used in liquid lines where cold, thick oil or impurities may be present, it is recommended that the standard spring be replaced by a special spring. The snrva non-return check valves are available with salient features like ensure correct direction of flow; prevents back-condensation from warm evaporator to cold evaporator; and fitted with damping piston for installation in discharge lines where pulsation may occur from the compressor.